Web heating device

Abstract

For use in forming a web W into a tubular shape, and heat-sealing an inner surface of outer edge of the web and an outer surface of inner edge of the web to provide a lap, a web heating device for heating the outer edge inner surface of the web with hot air before heat-sealing comprises transport means for transporting the web W along a predetermined path, a nozzle 27 having hot air outlet openings 67 directed outward as opposed to the outer edge inner surface of the web W to be transported by the transport means, and a baffle plate 32 so disposed as to be opposed to the hot air outlet openings 67 with the outer edge of the web W positioned therebetween.

What is claimed is: 
     
       1. A web heating device for use in forming a web into a tubular shape, and heat-sealing an inner surface of outer edge of the web and an outer surface of inner edge of the web to provide a lap, the web heating device being operable for heating the outer edge inner surface of the web with hot air before heat-sealing, said heating device comprising: transporting means for transporting the web along a predetermined path;   a nozzle having hot air outlet openings directed outward as opposed to the outer edge inner surface of the web to be transported by said transporting means; and   a baffle plate for deflecting said hot air so disposed as to be opposed to the hot air outlet openings with the outer edge of the web positioned therebetween, wherein said nozzle and said baffle plate is retractable from the outer edge and inner edge of the web.   
     
     
       2. A web heating device as defined in claim 1, wherein said web heating device further comprises tensioning means for tensioning the web so that the outer edge of the web can be positioned between and spaced apart from said nozzle and said baffle plate. 
     
     
       3. A web heating device as defined in claim 2, wherein said tensioning means comprises a dancer roller having the web reeved therearound and disposed on the path upstream from said nozzle with respect to the direction of transport of the web. 
     
     
       4. A web heating device as defined in claim 3 wherein the nozzle and the dancer roller are housed in an aseptic chamber. 
     
     
       5. A web heating device as defined in any one of claims 1 to 4 wherein the baffle plate is formed with a cutout or a hole for inspecting the web therethrough. 
     
     
       6. A web heating device for use in forming a web into a tubular shape, and heat-sealing an inner surface of outer edge of the web and an outer surface of inner edge of the web to provide a lap, the web heating device being operable for heating the outer edge inner surface of the web with hot air before heat-sealing, said heating device comprising: transporting means for transporting the web along a predetermined path;   a nozzle having hot air outlet openings directed outward as opposed to the outer edge inner surface of the web to be transported by said transporting means;   tensioning means for tensioning the web so that the outer edge of the web can be positioned between and spaced apart from said nozzle and said baffle plate, wherein said tensioning means comprises a dancer roller having the web reeved therearound and disposed on the path upstream from said nozzle with respect to the direction of transport of the web; and   a baffle plate for deflecting said hot air so disposed as to be opposed to the hot air outlet openings with the outer edge of the web positioned therebetween, wherein said nozzle and said baffle plate is retractable from the outer edge and inner edge of the web and wherein said nozzle and said dancer roller are housed in an aseptic chamber.